Which of the following best describes simple carbohydrates?

Simple carbohydrates are best characterized as monosaccharides and disaccharides. Monosaccharides are the most basic form of carbohydrates, consisting of single sugar molecules such as glucose and fructose. Disaccharides, on the other hand, are composed of two monosaccharides linked together. Common examples include sucrose (table sugar) and lactose (milk sugar). These types of carbohydrates are quickly absorbed by the body, leading to rapid increases in blood sugar levels.

In contrast, other choices refer to different types of carbohydrates. Long chains of sugar molecules describe complex carbohydrates, which are polysaccharides and consist of many monosaccharide units joined together. Fiber and starch also belong to this category, as they are made of longer chains of glucose units. Complex polysaccharides, which include starch and certain fibers, are not classified as simple carbohydrates because they have a more complex structure and slower digestion process. Therefore, the designation of simple carbohydrates specifically aligns with the presence of monosaccharides and disaccharides, making it the correct choice.